Electrically controlled switching devices such as relays and contactors typically employ an electromagnetic coil that charges to open or close a switch. Improvement in the speed and weight, and simplicity of manufacturing these electrically controlled switching devices can be improved.
Some circuit interruption devices, which include circuit breakers, ON/OFF switches and the like have employed shape memory alloy (SMA) elements as a thermal circuit breaker or as a replacement of a solenoid in these devices. It can be difficult to quickly and accurately heat the SMA element at various operating temperature requirements. At a lower temperature, more energy is needed to raise the temperature of the SMA element to achieve a change in shape of the SMA element, but at a higher temperature less energy is required to avoid permanent damage to the SMA element.